▎ 摘　　要

NOVELTY - Preparing graphene immobilized enzyme catalyst involves taking oxidized graphene (concentration 2 milligram/milliliter) aqueous solution, adding appropriate amount of sodium hydroxide, and sodium chloroacetate, placing at water bath, ultrasonic reacting for certain period of time, neutralizing by using diluted hydrochloric acid, washing to neutralizing by de-ionized water, freezing, and drying to obtain surface carboxyl activated graphene oxide powder which is sealing, and storing. The acid activated graphene powder is added to volume of 0.2-0.3 mole/litre hydrochloric acid solution. USE - Method for preparing graphene immobilized enzyme catalyst used for catalyzing green synthesis of fatty acid ester (claimed). ADVANTAGE - The method enables to prepare graphene immobilized enzyme catalyst in simple and cost-effective manner, and has high conversion rate. DETAILED DESCRIPTION - Preparing graphene immobilized enzyme catalyst involves taking oxidized graphene (concentration 2 milligram/milliliter) aqueous solution, adding appropriate amount of sodium hydroxide, and sodium chloroacetate, placing at water bath, ultrasonic reacting for certain period of time, neutralizing by using diluted hydrochloric acid, washing to neutralizing by de-ionized water, freezing, and drying to obtain surface carboxyl activated graphene oxide powder which is sealing, and storing. The acid activated graphene powder is added to volume of 0.2-0.3 mole/litre hydrochloric acid solution, stirred at 45 degrees C for certain period of time, ultrasonically dispersed for 20-30 minutes. The dispersion is added to 5% (3,4-dihydroxyphenyl) ethylamine aqueous solution, added appropriate amount of interfacial reagent FG-6, stirred vigorously for 0.5-1 hours to fully chelate. The test solution is centrifuged, resulted solid is repeatedly washed with deionized water until pH of washing solution is neutrallized, vacuum dried at 90 degrees C for 15-24 hours to obtain surface-activated group-modified functionalized graphene oxide (denoted A). The certain amount of surface-activated group-modified functionalized graphene oxide is added to certain volume of tris-hydrochloric acid buffer (50 millimole/litre, pH 7.0), ultrasonic dispersed for certain time, added 50% of glutaric dialdehyde solution, stirred at room temperature for period of time, centrifuged, seperated, and washed with deionized water to obtain solid product. The solid product is added to tris-hydrochloric acid buffer (0.05 mole/litre) which contained certain amount of lipase at pH 7.0 at temperature of 4 degrees C for predetermined period of time followed by centrifugation, separated, and washed to obtain graphene immobilized enzyme catalyst particle (denoted B), freeze-dried, and stored at -20 degrees C.